diff --git a/nummi/category/templatetags/category.py b/nummi/category/templatetags/category.py
index e344471..5f76341 100644
--- a/nummi/category/templatetags/category.py
+++ b/nummi/category/templatetags/category.py
@@ -23,7 +23,7 @@ def category_plot(transactions, **kwargs):
             "categories": categories,
         }
         | categories.aggregate(
-            max=Greatest(models.Sum("sum_m"), models.Sum("sum_p")),
+            max=Greatest(-models.Sum("sum_m"), models.Sum("sum_p")),
             total_m=models.Sum("sum_m"),
             total_p=models.Sum("sum_p"),
             total=models.Sum("sum"),